The purpose of the proposed research is to assess the effects of residential segregation (particularly the type which excludes blacks from the suburbs), in a context of decentralizing employment opportunities, on unemployment among urban blacks. Past research has presented conflicting findings regarding effects of segregation and access to jobs among blacks on black unemployment rates. Plausible theoretical arguments have been presented both for and against the hypothesis that segregation and access are significant factors influencing black urban unemployment. Through the use of more recent data, a large sample of cities, and more appropriate measures of segregation and access, the present study may offer more conclusive findings than past research on this topic. Data for 237 Standard Metropolitan Statistical Areas (SMSAs) will be obtained from the Censuses of Population and Housing (1970) and of Manufacturing, Retail Trade, Wholesale Trade, and Services (1967 and 1972, using interpolation to estimate 1970 figures), and from published data for 1970 on residential segregation. Correlation and regression analysis will be used to assess the effect of various measures of residential segregation, job decentralization, and job access on black unemployment (both absolute level and level relative to white unemployment), with control for such factors as region and overall unemployment level.